I went through a similar thing with my sisters phone, to help her set it up, i put in my account untill she had created one. long story short yes, you have to do factory reset.
we backed up the phone via KIES, never really tried the card backup? it appears at bit late now, all i can suggest at the moment is losing alot of stuff sux bad, but you now have learnt alot... more than others and its NOW you can set the phone up to how you want to starting fresh. to recover data is probably possible, getting someone to do it is most unlikely.
-i made my gmail account first on a pc, punching in names numbers etc....so that anything happens to my phone, its backed up. anythin changes - i sync it.
-fuk the samsung account. really. only good thing about it is DIVE and i got stuff all support too. too them over a month to tell me "you cant get DIVE in AUST anyway"
there are other apps n programs for losing your phone kinda thing. i have just put mine on my house insurance. My ISP can take the side of locking it out and ill just get another if it gets stolen or whatever.
good luck n try to stress less, it will only make other things harder too.
